1. Field of the Invention
This invention concerns a stylus type recording instrument, in general, and more specifically it relates to an improvement of a stylus type recorder. It is especially applicable to portable recording apparatus of the type carried by a pipeline surveying pig.
2. Description of the Prior Art
In connection with data recorders, and particularly where such recorders are for use in pipeline surveying it has been found that if the recorder is subjected to high acceleration forces, there is a tendency to cause false indications. Thus, in regard to the data being recorded by the recording instrument, the shock accelerations can cause physical movement of a stylus employed by the recorder. This creates events on the record that look like genuine events which are created in response to the data being recorded.
Consequently, an object of this invention is to provide recording apparatus that has a provision for locking the recording stylus until data to be recorded is received. Thereafter, the stylus is then relocked into neutral position immediately following the recording of an event.